Bonding performance of universal adhesives in different etching modes

Area of Science:

• Dental Materials Science
• Adhesive Dentistry

Background:

• Universal adhesives (UAs) offer versatile application modes in dentine bonding.
• Understanding their performance in different etching modes is crucial for clinical success.

Purpose of the Study:

• To compare the microtensile bond strength (μTBS) and dentine resin penetration of three UAs.
• To evaluate the effect of self-etch versus etch-and-rinse modes on UA performance.
• To assess the impact of thermocycling on UA bond strength.

Main Methods:

• Three UAs were tested in self-etch and etch-and-rinse modes on human molars.
• Microtensile bond strength (μTBS) was measured after 24h storage or 5000 thermocycles.
• Resin penetration into dentine was visualized using confocal laser scanning microscopy.

Main Results:

• Etching prior to UA application increased resin tag length and hybrid layer thickness.
• No significant difference in μTBS was found between self-etch and etch-and-rinse modes for any UA.
• Thermocycling did not significantly affect the μTBS of the UAs.

Conclusions:

• Dentine etching improves UA penetration but does not enhance bond strength at 24h or after thermocycling.
• Universal adhesives demonstrate consistent bond strength across application modes, ensuring clinical reliability.